Just got out to Bodega Bay with my family. I am teaching at the Bodega Bay Phylogenetics course tomorrow and we have made it an annual tradition to come out for a few days around the time when I teach at this course. This trip we rented a small house (3 days for the price of two – cheaper than a hotel …). We just got here a few minutes ago and while I was looking up when my talk for the course was, my wife came over with a bottle of hand soap and asked “Is this the same chemical”? What she was referring to methylisothiazolinone. And lo and behold – check out the ingredients:

Now why on Earth would we care about this specific chemical? Well, because of something that started about a month and a half ago. One morning, my wife brought the business section of the Saturday New York Times over to me while I was working in our office and asked if I had seen the article on the front page.

The article was: An Unexpected Reaction: Growing Scrutiny for an Allergy Trigger Used in Personal Care Products by Rachel Abrams. I said “I had seen the headline but not the article yet.” She said “We should see if this chemical is in any of the things we use and if it might be contributing to the rash (our son) has been getting occasionally.” He had been having some issues for a year or so with unexplained rashes – and despite multiple doctor’s trips – no solution.

So I read the article quickly. It discussed a chemical called methylisothiazolinone which, annoyingly, has been added to all sorts of personal care products relatively recently by a variety of companies. The chemical had apparently been causing rashes and allergies in lots of people.

So – the first thing my wife and I did was to go to the number one candidate culprit – the wipes he was using occasionally? Our son liked using wipes to clean his hands when we are out and about and also liked using them for, well, booty wiping, occasionally, again especially when we were out and about and the toilet paper at some bathroom was rough). So I looked at the wipes.

You got it.

And, well, I could not believe it. There on the list of “ingredients” in the wipes, was methylisothiazolinone. What the *$##? Seriously? Could this be the cause of all the problems?

Well, so I decided to dig into this chemical a bit more. And well, I became extremely stressed and pissed off at many companies out there. See for example these links:

Jesus. Really Target what the heck were you doing putting this in baby wipes? So we stopped using those wipes. Threw them all away. And lo and behold my son’s rashes completely went away. The best explanation I have is that the wipes were causing the rashes. I would bet anything it was the methylisothiazolinone though of course I don’t have direct evidence that it is the culprit. Nevertheless, given the articles I have read (including those above) we have been paying more attention to the ridiculous crap that some companies put in their skin care products. As an aside, we actually pay attention to almost all of the stuff we use around the house, these wipes just slipped through the cracks

Anyway – back to Bodega Bay. Thank goodness my wife pays attention to details. My kids had used the soap when we first got here a few minutes before she found it. But we got them to rinse a lot and hopefully it will not cause any problems. Nevertheless, I just am continually stunned by chemicals that companies put in products like soaps and lotions and other things. This is in a way connected to obsessive germophobia seen spreading around the world. Methylisothiazolinone is a “biocide” and is being used in these products as some way to keep them sterile and to have them be able to kill germs (and also as a marketing gimmick). But of course, we should not be trying to kill everything in the world around us. Doing that is a bad bad bad idea. I wonder – could the “allergic” skin reactions people are having to this methylisothiazolinone actually be due to it altering microbiomes and then that alteration leads to problems? I wonder. I won’t test that idea on my kids or myself. But I do wonder.

Two brief comments:
(1) Many (most?) consumer products are not labeled with their ingredients.
(2) Isothiazolones are used as antifungal agents in household paints, lacquers, and adhesives. See R Nagorka et al., Isothiazolone emissions from building products, Indoor Air 25, 68â€“78, 2015. Because the chemicals are semivolatile, exposure can occur by inhalation (and other mechanisms) for extended periods after use. (Access to the article is free. If I was better with HTML I’d put in the link, but copying and pasting the title into Google Scholar will get you there quickly.)
– Bill Nazaroff

As for the article – scary to be honest. What are we doing with allowing all of these antimicrobial / antifungals / toxins in all of our household products? I include the “Practical Implications” from the paper below for those interested:

Numerous indoor products are preserved by isothiazolones, which are known as relevant contact allergens. Due to its strong sensitization potential, the in-can biocide 5-chloro-2-methyl-2H-isothiazol-3-one (CIT) has been largely substituted. Our findings show a relatively high application of the currently used isothiazolones 2-methyl-2H-isothiazol-3-one (MIT), 1,2-benzisothiazol-3-one (BIT), and 2-octyl-2H-isothiazol-3-one (OIT) for in-can and for dry-film preservation. Emissions from these isothiazolones in the indoor environment, depending on parameters like the biocide concentration in the building product and the product consistency, could be observed over a long period of time. These emissions constitute an unnecessary exposure and may lead to sensitization issues for building occupants.

The short story is that chemicals are innocent until proven guilty in US commerce and regulation. If the chemical provides some real or perceived functional benefit for a product, and if it is not already known to cause harm to humans or the environment, then it is a candidate for use. In the US, we have a long history of trying something in this way, discovering that it was harmful, and then removing it (by regulation or voluntarily) from commerce. The European REACH system is trying to reinvent this process. We’ll see.

For more about the chemistry of the great indoors highlighting some of the broad range of compounds emitted from materials and products, here is a small sampling. Note that all three articles are from Atmospheric Environment, which is behind Elsevier’s paywall. But rogue copies can be found for two of the three from Google Scholar. And abstracts are freely available, of course.

Notwithstanding the sensationalistic title, the book is sober, thoughtful, and thought provoking. Her focus is on the environment writ large. The view of some (including me) is that much of the exposure to the endocrine disrupting chemicals discussed by Colborn et al. occurs indoors as a consequence of chemicals used in building materials, furnishings, household products, and other ordinary items of commerce.

If you are allergic or sensitive to any products containing Methylisothiazolinone please check out this website, (http://hpd.nlm.nih.gov/) which is the US Department of Health and Human Services website. It has a comprehensive list of products (hundreds of products that contain the preservative/chemical in them, and then just type methylisothiazolinone in the search box; it will list all products known to carry this.

I found a laundry detergent (PURCHELL POWDER) which is free of this METHYLISOTHIAZOLINONE, I was hospitalized for over 3 days with blisters the size of dimes all over the top of my hands. I only found out later by getting patch tested it was this preservative/chemical that caused the contact dermatitis or violent reaction.

PLEASE BE AWARE, PURCELL POWDER DOESN’T HAVE IT IN IT; HOWEVER, THE PURCELL LIQUID DOES! Hope this helps everyone out in looking at the comprehensive list of products ahead of time before you buy one, only to find out after the fact that it’s in these products in some form.

Just found this article and your link and I’m so thankful. I’ve been dealing with horrible, painful contact dermatitis on my face for months and I finally figured out it is methylisothiazolinone. My doctor and allergist were no help at all. Thank goodness for the internet in situations like this. I am attempting to eliminate it completely from my world and this will help so much!!! Thank you, thank you, thank you!

I so agree with this – within the last ten-fifteen years, I have had so many skin issues and in fact have blown up like a blow fish three times in the last 8 years – due to moisturizers and the last time – exposure to chemicals during a manicure and pedicure. Won’t be doing that again. I frequently have no skin on my hands due to exposure to MI as well as formaldehyde. I was finally able to get a doctor to test me for allergies after letting the dermatologist know after the second reaction. My family doctor just kept saying it was sensitivities – its no big deal – Sorry I disagree!
Now I have a two page list of chemicals to avoid in self care products but trying to get ingredient lists for laundry detergents and dish soap is harder – that’s how I found your article. I was searching again since I have been washing dishes and toys as I clean up my classroom and now have no skin left of the tips of 7 of my finger and the palms are peeling. Guess its time to do more research. I hate wearing gloves. why can’t they stop putting this stuff and fragances in products. One skin care line that I love and can safely use is Vanicream and Free and Clear products- try those for your kids.

What we really need is a list of products that do not use this chemical. My daughter found out that she was highly allergic to MCI about two years ago. It is really hard to get away from it. And some manufacturers will say they don’t use it and then six months later they start using it. We need reliable labeling and we need awareness to how bad these chemicals are. Methylisothiazolinone, Benzisothiazolinone and Isothiazolinone are all part of the same chemical family and actually have a facebook page for people who are allergic to them.
Thanks for bring more awareness to this problem.

The preservative methylisothiazolinone (MI) is the American Contact Dermatitis Society Contact Allergen of the Year for 2013. Because the use of MI in cosmetics and toiletries in the United States rises, MI exposure also rises. Although it might seem likely that testing with methylchloroisothiazolinone (MCI)/MI would be adequate to pick up contact allergy to MI alone, the mix misses approximately 40% of allergy to MI, likely because of the low concentration of MI in the MCI/MI combination patch test. In Europe, several groups have documented frequency of allergy to this preservative of approximately 1.5%. The frequency of allergy to this preservative in the United States is unknown. If you are not testing for allergy to this preservative, you may be overlooking the importance of a very relevant preservative allergen that, to date, has managed to stay under the radar in the United States. This report reviews the background and reasons for adding MI to our routine screening patch testing series.

My son’s wife just died in the middle of January. Two weeks before her very, very short illness she started using a different hair product containing MCI/MI and began extensive itching especially around the back of her neck. No one thought to relate this to the change in hair product. Suddenly over the weekend of January 9th she became lethargic, headache,neck ache, etc. and a fever of 99.6 On the Tuesday, it went to 104 and she became unresponsive, my son called an ambulance. Her temp went up to 105.7 twice, never really dropped and was unofficially brain dead within 48 hours. She was thought to have menningitis, tested for known bacteria and viruses -none were positive. Once she passed an autopsy has been done and still no known viruses or bacteria is showing up that could have caused this. Her death is listed as viral mennigit encephalitis. We are wondering if there is a possible link to the MCI/MI. We did ask the doctors to look for this in the autopsy but were told this was a very unlikely possibility. My daughter-in-law was 37 years old. Is there a research link that can look into this?

I note – I am not an expert in the clinical side of effects of MI or MCI or related chemicals. However, there are cases of infections being spreads due to contamination of personal care products like cosmetics and shampoos. Such cases have as far as I know nothing really to do with MI or MCI or any ingredients in the products but instead due to some sort of contamination during production. Examples include these:

In general, meningitis can come from many sources and is caused by many different kinds of organisms. The way to figure out whether there is any way to track the source of your daughter in law’s illness would probably be to get public health officials of some kind involved. You might want to try contacting local public health agencies (e.g., in the US there are agencies for most counties and states).

Thank you Jonathan for this link to products I can replace mine with! I just had patch testing done this week and had a wicked reaction 3+ to Methylisothiazolinone! I am also extremely upset to see where this chemical is being added….especially how many baby products and “free
and clear” or “all natural” products have it.

Abstract
Isothiazolinone is known to be a sensitizer and a frequent cause of contact dermatitis in adults. Cases of contact dermatitis have also recently been reported in children. Derivatives of isothiazolinone, such as methylisothiazolinone (MI) and methylchloroisothiazolinone (MCI), are commonly used in the care products of babies and children. This allergen should not be missed.

My daughter is allergic! We figured it out about 6 years ago after fighting the rash reaction to the Luvs baby wipes for over 6 mos. We now check the label on everything!! I would say over half of what we check has this ingredient including anti bacterial hand soaps!! Very frustrating!! Oddly enough, it seems as though methylparaben (sp) is a similar ingrediant with a similar function and she’s not allergic to it!!
Thank you for posting this!!

This chemical is a huge problem here in the UK. I live in England and have had a dreadful reaction to this nasty chemical. It has taken many visit to my GP and eventually a referral to my first a dermatologist at my local Hospital, then, after much trial and error with creams, lotions etc., I was eventually referred to yet another Dermatology Department at another Hospital for a comprehensive patch test. Of course, the culprit, Methylisothiazolinone, in fact anything with isothiazolinone in it. So far, I have had this problem for just over 3 years! Yes, 3 years of pain and itching, absolutely awful itching 24/7. I belong to a FaceBook group, where people have already posted photographs, including myself. Obviously, different people have had different reactions to various parts of their bodies. Some, just their face and hands, due to moisturisers or baby wipes. Some, like me have had a reaction all over their body, from head to toe, because of using products like shampoo, shower gel, toothpaste, liquid laundry detergent and soft rinse. Even after disposing of all and everything in my home containing the chemical over 12 months ago, I am still in the process, under the care of a Dermatologist, of trying to get my skin repaired and back to what it once was! My consultant eventually prescribed me a drug ( 12 months ago now) to take orally, that is given to transplant patients to stop their new organ being rejected! A drug to suppress my immune system so that my body can cope with trying to repair itself. I still constantly itch and, I still have some red, sore bumps which scab over on my legs, buttocks, back, shoulders and arms. Areas that have healed have left white marks on my skin, which just goes to show have far down into skin tissues this chemical reached and the damage it caused. Jill Brodie. England. UK.

I couldn’t help but be concerned for the drug the dermatologist is giving you to suppress your immune system so your body can repair itself. Maybe I’m over thinking this but a drug to stop your immune system is going to stop your immune system. Period. How can your body repair itself without the immune system? Doctors are very unaware of safe, non-toxic products that can help with skin issues. Many product ingredients actually stop drugs from being effective. Tamoxifen, for example, is ineffective if you are using most over-the-counter shampoos or body washes which contain parabens (anything containing Methyl, Butyl, Ethyl, Propyl). They seem to only know how to prescribe products with chemicals. It’s not their fault – they’re still just unaware. I am a wife, mom, teacher, female with some allergies and the older I get I am finding more products I’m sensitive to. I’ve been to an allergist and dermatologist. I now know it’s bc of all the chemicals that are being added to products that companies believe are helping us. Hold that thought for a minute. Most companies and manufacturers bottom line is profit. Even if an ingredient isn’t safe, most often they’re going to use it anyway to sell it and make money. It’s a multi-million dollar industry, after all.

Two years ago I was struggling with a rash around my mouth, a rash on my chest. A rash would pop-up almost anywhere, whenever; sometimes big, sometimes small, but non-the-less irritating, ugly and uncomfortable. I was introduced to Ava Anderson Non Toxic products which have no harmful ingredients. All the ingredients are organic and safe. Now, there are some people who are still allergic and/or sensitive to some natural ingredients, but there is something for everyone, even pets! I hope this helps. I love NOTHING better than being able to help people find solace in pure, healthy and affordable products and a company whose bottom line is safe & healthy, not dollars. I hope this helps.
Jana Loeschen, #5293
Ava Anderson Non Toxic consultanthttp://www.avaandersonnontoxic.com/janakay

I was diagnosed with an MI allergy in 2014, after suffering for 12 years. I had been to multiple allergists and dermatologists, and none of them even thought to test me for chemical allergies. I wound up discovering my allergy on accident after pushing my doctors around to get me a propylene glycol allergy test at UCSF (I was going insane). Only the folks at UCSF seemed to be familiar with MI and MCI allergies as being “everywhere.”

Despite the prominence of MI causing sensitization, most allergists and dermatologists still seem to be clueless about how rampant of a problem this chemical is. Every MI victim I know has a story similar to mine.

That’s all build up to say: Thank you. Thank you for being a medical professional and professor who is aware of the problem this chemical can cause. You can have more of an impact on awareness than just sufferers can. WIth increased awareness, people will get diagnosed quicker, and labeling requirements will come into effect.

Thank you for helping to spread the word, especially educating other medical professionals.

Thank you for writing about this issue! For several years, I have run a Facebook group for people affected with MI/MCI/BIT allergy and have watched the epidemic unfolding all around the world. The most recent research coming out of Europe shows the population estimates as being closer to 8%-10% affected there, and I would venture to say we’re on a similar pathway here in the US.

One particularly disturbing issue is that in the US, the problem can’t be easily solved here because it’s equally shared as a responsibility between the EPA, FDA and other fed/local departments. Right now, the EPA has said they’ll look more closely at it (we lobbied them last fall not to rubber-stamp the registration approval in the US when it came up for review), but it will be 2020 before they have a “working plan”. To give you a sense of how dangerous this game is we’re playing, the European studies have shown that 5 ppm can be sensitizing, and housepaint formulas are allowed up to 1000 ppm! Airborne reactions were never anticipated in the original safety studies.

Now that your son is sensitized to MI, he’ll have to be very careful of craft paints at school, swimming pool chemicals, magic markers, toilet paper (it’s used as a slimicide in paper production, and is found in Charmin and Scott tissues), leather treatments (furniture and car seats), air conditioning treatments, etc. It’s not easy to avoid and getting harder by the day… It’s a good thing you caught it early, though, and can help him navigate. It’s a life long problem. In addition to the rash reactions, there have been reports of vision loss (temporary and some permanent scarring), muscle/nerve reactions, and secondary infections.

I too just underwent allergy patch testing, 3 weeks ago, and I STILL have a welt where I tested positive for the allergy. My hands were so cracked and bloody and swollen I couldn’t move them. I have thrown out my shampoo & conditioner (finally realized why my head always itched!) and after literally slathering on “healing lotion” (Eucerin) I learned THAT is used as a preservative in it, so I was only making my hands worse and worse. Now I’ve just been using pure coconut oil and bar shampoo, and taken to carrying my own soap with me for public places. I’m curious if anyone has found a liquid dish soap that does NOT contain it. (Mrs. Myers & Method does). Even when I wear rubber gloves, it stays in the washcloth and unless I never ever touch the washcloth without gloves, I continue to have a rash in the same spot on my hands. It would be easier to just find a brand that doesn’t have it.

Ava Anderson Non Toxic Dish Soap does not contain it. In fact, non of our products contain it. I am a consultant for AANT and she, Ava Anderson, and her family have devoted their lives to developing safe, non-toxic products. you can order through my website at http://www.avaandersonnontoxic.com/janakay and follow the prompts. I hope you find other products that are well suited for you, also!

Hi Freshgreenkim. I recently (6 weeks ago) FINALLY found out WHY i’ve been scratching myself into a bloody pulp for the last 3 years! And why i’ve lost about 1/3 of my hair and some of my eyebrows! And the CONSTANT BURNING and STINGING and THROBING!!

I guess what they say is true. “The 9th times the charm”. As in 9 separate Dermatologists and or Allergists. Yes, 9. And ONLY 1 Dermatologist guessed that I had an allergic reaction to something. She (THANK GOD) referred me to her fellow Emory colleague for patch testing, and VOILA!

MYSTERY SOLVED! And I am now on the very bumpy road to a hopeful recovery. However, my scalp may NEVER fully recovery, and my hair may never grow back in some areas. But at least I’m not doomed to a lifetime of miserable and life-altering, and embarrassing ITCHING!!!

If you can’t find Ava Anderson Non Toxic products, I suggest Free &Clear products and “Home Free” Dishwashing Liquid. I purchased all items at Natlallergy.com. Though I’m sure that you could find them on Amazon as well. I price compared, and Natlallery.com was cheaper.

I have a horrible allergy to this. According to my dermatologist it could take up to three days to have a reaction, so I don’t always know what it was that I last touched. A lot of cleaning products do not even list their ingredients anymore, industrial-strength products are not required to list it either, because it supposed to be safe. But makes my eyes well up some times to the point that I can’t see, and I got a rash last summer that lasted for three months. I scratch so bad that I still have scars months later. Scary is its in a lot of paper products, he could be found in some toilet paper and tissues. They don’t list it all!

For those scars I have found that a combination of baking soda, lemon juice, and a little bit of water mixed into a paste and put on your skin for about ten minutes makes the scars fade very fast. You can also use peroxcide, lemon juice, and water and leave it on. Lemon juice is great at fading scars. I had terrible scars from this MI crap and these got rid of of them within 4- six weeks.

Torri, I also have the MI allergy. Liquid All Free and Clear laundry detergent doesn’t seem to bother me. I think the concentrated version may contain MI, however. You may check into that. Good luck to all of you. This allergy can sure make daily life tricky.

I am so grateful to have found this post and link. I got the results to my patch test today (36 allergies tested) and I came up positive for Isothiazolinone. A 3+ on the whatever scale.
I got home from work and found methylisothiazolinone in my shampoo (Head and Shoulders), body lotion and a couple household cleaners (Myers). Put it all in a bag.
I am shocked to see that laundry detergent, nor toilet paper typically put the ingredients on the packaging. That makes zero sense considering how close to the body those products end up.

paper pulp processing has used isothiazolinones as antislime control sludge control for decades. its all in there. correct. bingo. plastics, OIT in PVC. yes.
adhesives? probably yes, but Proprietary confidential trade secrets as supported by FDA currently, so youll never know. legislation needs overhaul. support this overhaul. look at Bill S. 1014
personal care products safety act. Feinstein. write in, call in.
then look at the EPA and design for the environment, safer choice new seal of approval allowing these skin sensitizing ( possible?neurotoxins- see pennsylvania study on MI MIT neurotoxicity studies) in all green products… designed for the environment ( but not for your skin)
see 2014 – US EPA and Industry Denialhttp://www.epa.gov/oppsrrd1/REDs/factsheets/3092fact.pdf
The EPA reviewing MI re-registration in the US in 2014 as a biocide (note that Dow Chemical is the largest producer of MI). Their original statement stresses it’s an “acceptable safety risk” for humans based on research from the 80s, but they do note that it can cause sensitization, which is where one becomes allergic after repeat exposure.
and see: “Abnormal visual processing and increased seizure susceptibility result from developmental exposure to the biocide methylisothiazolinone” (Neuroscience, 2012)http://www.sciencedirect.com/science/article/pii/S0306452211014497
Excerpt from study done on frogs: â€œWe find that MIT exposure results in deficits in visually mediated avoidance behavior and increased susceptibility to seizures, as well electrophysiological abnormalities in optic tectal function, without any effects on overall morphology, gross anatomy of the visual projections, overall visual function, and swimming ability. These effects indicate that chronic exposure to low levels of MIT results in neural circuit-level deficits that result in abnormal neurological function without causing increased mortality or even gross anatomical defects. Our findings, combined with the fact that the long-term neurological impacts of environmental exposure to MIT have not been determined, suggest a need for a closer evaluation of the safety of MIT in commercial and industrial products.â€

My husband developed rashes after using 2 different Neutrogena sunscreen lotions. It took him maybe a week to realize it was the sunscreens, but once he stopped using them, the rashes went away. Funny thing is, he is able to use another Neutrogena sunscreen spray with no problems. However, it wasn’t until recently I think that methylisothiazolinone may be the culprit. I compared the ingredients and sure enough, the two problematic sunscreen formulas contain this ingredient, but the sprays do not.

This ingredient is now either banned or has its use restricted in some European countries, Japan, Australia, and Canada. The US is always behind these countries in product safety thanks to the power of our corporate interests. I’m all for free markets, but unregulated dangers is where I draw the line.

the FDA has no current control over these reports, currently there are only 2. yes 2 adverse reactions to named specifically Methylisothiazolinone, (MI or MIT) as used in cosmetics. where are the reports going? FOIA? anyone?
there are many more versions and cross reacting isothiazolinones…
MCI
BIT
OIT
DCOIT
BBIT etc etc

I am allergic to Methylchloroisothiazolinone. It is hard to find products that do not contain it. Well, my dermatologist gave me this book of safe products but my challenge is finding the products. Typically the way it goes is that when i find one, the store shortly discontinues carrying it. This has made for extreme frustration and I am feeling that I am going to become an online shopper only because it is my only option. I feel the same way about these unnecessary ingredients as I do dyes. Don’t over produce and then we don’t have to worry about shelf life. Or find a chemical free way! As for dyes……who cares what it looks like. I don’t need the color of my soaps or lotions to be pretty. I just want a safe, effective product.